Statistics do not favour the immediate operation, for although some surgeons have obtained good results, the mortality with others has been considerable. Thus König,[68] on the one hand, records seventy cases operated on in the first month with but one death; whilst Hermann[69] gives 52·4 per cent. as the mortality of the operation during the first three months of life, and Gotthelf[70] 50 per cent. for a similar period. The latter cannot but be considered as an extraordinarily high death-rate, and possibly antiseptic precautions were not carefully observed. Trendelenburg[71] reports 44 cases treated in the course of three years with seven deaths; the infants were between three and six months old. Fifteen were simple cases, with one death; twenty-one were complicated, with two deaths; and eight most complex forms, with four deaths. Only one died within a fortnight of the operation; the remainder from intercurrent maladies. Still, however, he reckons the death-rate during the first year of life of children operated on as 41·6 per cent., explaining it by malnutrition and the want of intelligent artificial feeding. Fritzsche reckons the mortality during the first two weeks after operation as about 5 per cent., but even this is higher than I should consider consistent with the results of British surgery. My own personal experience has been much more satisfactory, and the above figures are much too high to represent my results. Out of between 300 and 400 cases treated between the fourth and eighth weeks, _i. e._ by the early operation, I have had no death as an immediate result, but several have died subsequently from intercurrent maladies or defective nutrition. I attribute this success largely to the fact that I never operate upon out-patients, but always take the precaution of carefully preparing and watching them for a few days prior to operating. In the practice of the late Sir W. Fergusson the one or two fatal cases which I recollect occurred in children who were taken home immediately after the operation. It has been claimed for the deferred operation that convulsions are liable to ensue when an infant under six months is operated on, and also that the interdiction of nursing impairs nutrition; but this has not been my experience. From a consideration of the foregoing facts, it would appear that from the fourth week to the third month is the most favorable period for interference, and that at which the greatest proportion of success has been obtained. In conclusion, whilst fully admitting that it is impossible to lay down rules which will meet every case, and that each must be dealt with on its own merits, I would venture to suggest the following propositions which may be helpful as a guide to practice: 1. That, _cæteris paribus_, it is important to close the cleft in the lip as early as possible.